I found this as a comment to an Amazon review (of someone else’s novel)

It’s not science fiction if the technology described is merely listed–to be science fiction, there needs to be an element of explanation; without explanation of any kind, whether through descriptions of use all the way through full expositions of actual or imagined physics, it is merely the panoply of science fiction, not actual science fiction. simply slapping labels on stuff–Gates, beings with many bodies, space stations, AI, sentient ships, guns that can shoot through anything–is imaginative fiction, no doubt, but without any aspect of explanation of the science behind it, remains only that and not science fiction. the test is pretty easy–if the plot works just fine without ever understanding anything about how anything works, it ain’t science fiction. if the plot can’t work without knowing the actual or imagined science, then it’s science fiction. and notice i say “science” and not just “rules.” rules are for fantasy. cause and effect relationships, whether speculated or actual, are the essence of science. magic (which is inherently fictional) only needs arbitrary rules at most–consistency is optional. conversely, science–even if fictional–absolutely requires internally consistent direct relationships within the described environment that is not contingent on anything in the story. in short, science fiction is not happening if what is offered is indistinguishable from magic. (yes, this is a Clarke corollary.)